May 7th: Beaufort Scale Day

The Beaufort Scale is the standard measure of wind speed used by Navies and Met Offices worldwide. It is named for its creator, Francis Beaufort, who was born on this date in 1774. Here are 10 things you may not know about the Beaufort Scale:

Hurricane Frances from space, photo by NASA

1. The scale began as a notation used by Beaufort in his daily weather observation journal, during his first command as captain of HMS Woolwich. As he rose in rank, and after an injury confined him to a shore based post as a hydrographer (producing sea charts), he carried on with the journal.
2. At fifteen, Beaufort was shipwrecked due to a faulty chart, which was why accurate charts and weather observation became so important to him.
3. Although there was nothing really new about charts for weather observation, they could be quite subjective and vary wildly in interpretation. Beaufort's scale was the first to be accepted as an objective standard.
4. The scale was officially adopted in the 1830s and the first ship to use it was HMS Beagle, since Beaufort had trained its captain, Robert FitzRoy.
5. In fact, Beaufort was also responsible for getting Charles Darwin onto that ship. It was Beaufort that FitzRoy approached about finding "a well-educated and scientific gentleman" as his companion on the voyage. Beaufort made some enquiries, and found Darwin.
6. At first, the observations used related mainly to the effect the wind was having on the sails of a Royal Navy frigate, ranging from from "just sufficient to give steerage" to "that which no canvas sails could withstand". However, as ships without sails became more and more common, it was extended to include the effect of the wind on the condition of the sea, and the trees on the land.
7. The scale ranged from zero to twelve initially, but in 1946 a further five classes were added in order to measure tropical cyclones.
8. Taiwan and China are the only nations which make use of the extended version today, as they are regularly affected by tropical cyclones.
9. Francis Beaufort was descended from French Protestant Huguenots, who fled the French Wars of Religion in the sixteenth century. He was born in Ireland. He used a cipher for many of his personal letters and journals; some of these hint that between the death of his first wife and his second marriage, he had an incestuous relationship with his unmarried sister, and was tortured with guilt about it.
10. As well as the wind scale, Beaufort is responsible for reliable and accurate tide tables for the UK.